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Bulgaria · Agentic SaaS development

SaaS Development for Bulgaria: Billing, VAT and E-Invoicing

A Ministry of Finance draft amendment to Bulgaria's VAT Act, in public consultation until 23 October 2026 and not yet adopted, would make VAT-registered suppliers established in the country issue domestic invoices to businesses and public bodies through the National Revenue Agency's NISSEF system from 1 January 2028. An invoice would count as issued only once the system generates a unique conformity code. For a SaaS founder that is a billing architecture question, sitting next to VAT, payment habits and EU Data Act switching duties.

At Curiosive, a studio in Ankara, Türkiye, AI coding agents write the CRUD screens, admin views, migrations and test suites, and senior engineers review every diff. Engineers design the multi-tenant data model, tenant isolation, plan and entitlement logic and billing webhooks themselves, because those are the parts where a mistake shows one customer's data to another or charges the wrong amount.

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VAT on selling SaaS from Bulgaria at home and across the EU

Bulgaria's standard VAT rate is 20%, with a reduced rate of 9%, and the mandatory registration threshold for transactions in the country is EUR 51,130 as of 1 January 2026. The draft amendment, if adopted, would raise it to EUR 75,000 from 1 January 2027. Selling to businesses in other EU countries usually means no domestic VAT on the invoice, because the customer pays at its own rate under the reverse charge, with several important exceptions. Electronic services sold to consumers in other EU countries are taxed in the customer's country, although below a EUR 10,000 threshold they may be taxed where the seller is established, and the One Stop Shop lets you declare that VAT through a single registration. In the product this means recording customer country, business or consumer status and VAT number at checkout, and keeping rates as data rather than code. Confirm your own position with an accountant.

E-invoicing and SAF-T timelines for SaaS companies in Bulgaria

Two reporting changes affect how a SaaS company stores invoices. The NISSEF draft would require structured e-invoices meeting the European standard under Directive 2014/55/EU for domestic supplies to locally established businesses, non-taxable legal persons and public bodies, from 1 January 2028 if adopted. At EU level, Directive (EU) 2025/516 on VAT in the Digital Age makes electronic invoices the rule from 1 July 2030, with intra-EU business supplies, including reverse-charge ones, under the new digital reporting. SAF-T is the second change. It has applied since 1 January 2026 to large enterprises with 2023 net sales revenue above BGN 300 million, and widens in phases until 1 January 2030, when VAT-registered micro-enterprises come in. We model invoices with an explicit status, so awaiting a conformity code is a real state rather than an edge case, and keep line data structured enough to export later.

Payments in Bulgaria: cards, blink and cash on delivery

The Bulgarian E-commerce Association's survey for 2024 found that cash on delivery made up 50.30% of online payments, cards 38.20%, bank and mobile payments 7.29% and buy now, pay later 4.21%. Cash on delivery cannot carry a recurring charge, so a consumer subscription asks many buyers to use a method that is not their usual one, which puts weight on card checkout and failed-payment handling. Under the PSD2 strong customer authentication rules, payment service providers may skip authentication for a remote payment of up to EUR 30 only while the payer's payments since the last authentication stay within EUR 100 or five consecutive transactions. The national instant-payment service blink, run by the National Card and Payment Scheme, offers 24/7 transfers by mobile number without an IBAN and launched euro instant payments on 3 December 2024. Separately, a seller covered by Ordinance No. N-18 must register its e-shop with the National Revenue Agency before it starts selling.

Multi-tenant SaaS: agents on the volume, engineers on the boundaries

Tenant separation sits in the data model, so an engineer designs it before agents write any screens: every table carries the tenant, every query is scoped, and tests deliberately try to read across tenants. Billing state comes from the payment provider's events, handled by idempotent webhooks so a redelivered event is not processed twice, and plan limits come from one entitlement layer. Because the EU Data Act's switching duties reach SaaS, per-tenant data export is planned in from the start. Agents then generate the CRUD screens, admin views, migrations and test suites around those rules. Our SaaS work includes Reveal Software (reveal.software), personal video onboarding built on Hono, Drizzle ORM and PostgreSQL, PicKey (pickey.ai) with subscription billing on Stripe, and Inspire Film (inspire.film) with per-title entitlement. Bulgaria trails Ankara by an hour in winter and matches it in summer, so reviews land inside both working days.

Proof

Published project examples

Reveal Software

Reveal Software

Release Coach AI

Release Coach AI

Inspire Film

Inspire Film

Poppin

Poppin

Zing Coach

Zing Coach

ChurchBee

ChurchBee

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Questions

The things people ask before starting.

What VAT rate applies to SaaS sold from Bulgaria?

The standard rate is 20%, with a reduced rate of 9%. Sales to businesses in other EU countries usually go out without domestic VAT under the reverse charge, and consumer sales of electronic services to other EU countries are taxed in the customer's country, with that VAT declarable through the One Stop Shop.

Will a Bulgarian SaaS have to issue e-invoices through NISSEF?

Not yet. As of October 2026 it is a draft amendment to the VAT Act in public consultation. If adopted, VAT-registered suppliers established there would issue structured e-invoices through NISSEF for domestic supplies to businesses and public bodies from 1 January 2028, so modelling invoice status now is cheap insurance.

Does a SaaS company in Bulgaria have to register its online shop with the NRA?

Yes, if Ordinance No. N-18 covers the business. A covered seller of goods or services through an e-shop must file its details with the National Revenue Agency, using a qualified electronic signature, before it starts selling. Remote card payments can then be recorded with a non-fiscal sale registration document instead of a fiscal receipt only if the sales software meets Article 52s.

Do EU Data Act switching rules apply to a SaaS sold from Bulgaria?

Yes, for SaaS sold as a data processing service, since 12 September 2025. Switching terms must be in a written contract, with notice of no more than two months and a transition of no more than 30 calendar days. From 12 January 2027 no switching charges are allowed. Services mostly custom-built for one customer are partly exempt.

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